All releases of Flex Bison C++ Template

Release Notes: A very subtle bug with the newly introduced
virtual yywrap() function in the FlexLexer class
was corrected. Depending on how the header was
included, the class contained the virtual yywrap()
function or not. These differing class
declarations lead to very strange NULL pointer
exceptions, because the different compiled objects
assume different class memory layouts. Ultimately,
the exprtest program always segfaulted.